High Blood Pressure, AFib and Your Risk of Stroke

What do blood pressure and the rhythm of your heart have to do with stroke risk? Plenty.

Consider this: About three out of four people who have a stroke for the first time have high blood pressure. And an irregular atrial heart rhythm — a condition called atrial fibrillation — is present in about one out of five strokes.

Stroke is a leading cause of death in America. It happens when a blood vessel that supplies blood to the brain is blocked or bursts. Nearly 800,000 Americans suffer a stroke each year.

High blood pressure is the chief culprit, and atrial fibrillation isn’t far behind. Yet there’s good news — you can easily do something about them. Your best defense is to avoid these heart conditions through a heart-healthy lifestyle. But even if you’re living with atrial fibrillation or high blood pressure, there’s still a lot you can do to lower your risk of stroke.

The Stroke Connection

The brain needs blood and oxygen. When that doesn’t happen and that crucial nourishment can’t reach the brain — either because of a clogged artery or a burst vessel — brain cells start to die.

For people with high blood pressure, the force of blood pushing against the arteries as the heart pumps blood is too high. That causes gradual damage to the arteries, including those to the brain. A weakened blood vessel may rupture in or near the brain, or diseased arteries may become blocked by a clot or plaque buildup.

Then there’s atrial fibrillation. That’s when stroke risk increases because the rapid heartbeat allows blood to pool in the heart, which can cause clots to form and travel to the brain.

High blood pressure is generally considered the most common controllable risk factor for stroke, but atrial fibrillation is the most powerful, said Ralph L. Sacco, M.D., professor and chairman of neurology at the Miller School of Medicine at the University of Miami and past president of the American Heart Association. “Somebody with high blood pressure has almost twice the risk of stroke than somebody without high blood pressure,” he said. “But someone with atrial fibrillation has more than five times the risk of stroke.”

“Because high blood pressure is so frequent, affecting tens of millions of people, it has a bigger impact on the number of strokes attributed to it,” Dr. Sacco said. “But atrial fibrillation is a more potent risk factor.”

The two risk factors are also related to each other: High blood pressure is a risk factor for atrial fibrillation. Middle-aged men and women with high blood pressure are at increased risk for atrial fibrillation later in life. “Then it becomes a double whammy, where you have high blood pressure as well as atrial fibrillation increasing your stroke risk,” Dr. Sacco said.

How to Reduce Stroke Risk

Stroke is not inevitable, even if you are among the millions with high blood pressure or atrial fibrillation. Preventing or controlling high blood pressure and atrial fibrillation can greatly lower your chances of having a stroke. Here’s how:

Stroke prevention is often the focus of doctor-patient conversations in atrial fibrillation, Dr. Sacco said. But for people with high blood pressure, “busy physicians don’t always rank discussions about preventing stroke as high as we’d like,” he said. “We have so many very effective medicines to treat high blood pressure and atrial fibrillation. If more patients with high blood pressure and atrial fibrillation are properly treated, we’re optimistic the number of projected strokes will go down.”

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